In a humid room at the University of Wisconsin?Madison (UW), large Tupperware boxes hold thick beds of gray fungi, pockmarked with holes and crawling with leafcutter ants. The boxes are home to colonies of two leafcutter species, Atta cephalotes and Acromyrmex echinatior, brought back from the tropical forests of Panama and Costa Rica by bacteriologist Cameron Currie and his colleagues, who study these insect agriculturalists and the fungus gardens they tend.